Intuitively, most people would accept this proposition as true: there are so few women in senior managerial posts that those who do succeed are almost bound to be better than your average male. But it is also demonstrably true; the way that highly-paid women earn their money appears rather different from the way in which highly-paid men earn theirs.
Our top women are almost exclusively performers, people whose pay is related in some direct way to their output, usually as writers or pop stars. Our top men, by contrast, are usually (though not exclusively) in business or finance: they are either entrepreneurs who have built up their own businesses, or commercial bureaucracts, people who have climbed corporate ladders to top positions.
Ten of the top 20 female earners in Britain were, according to a survey at the weekend by the Mail on Sunday, authors. (I have cheated slightly by classifying Baroness Thatcher as an author; earnings from her book, plus associated speeches, is why she has shot up the league, but of course she employed a team of ghost-writers to pen her tome.)
Of the rest, six were pop singers or former pop singers, two were supermodels and one was an actress. Only one of them, Anita Roddick, the founder of Bodyshop, was in business, and she squeaks in at number 20, with pounds 561,000 of earnings. Number one, the author Barbara Taylor Bradford, earned pounds 8.7m last year.
There is no comparable list for male earnings, for such lists tend to look at wealth, inherited or otherwise, rather than income. But a quick check of the pay of the chief executives of the 100 largest companies (all men) reveals that 35 earned more than Anita Roddick.
The high earners in the City are overwhelmingly male, as are the top professionals in the law, medicine and accountancy. The glass ceiling really does exist. However - and this is the important bit - if one looks at the very top of the earnings scale, and certainly at the new fortunes being made, there is a disproportionate number of men who are performers rather than bureaucrats. In that list of 100 company chiefs, only six earned more than pounds 1m, yet one could very quickly list half a dozen male 'performers' who earn far more: Sir Andrew Lloyd Webber, Paul McCartney, Mick Jagger, Elton John, Sean Connery, and the man who turned business into a performance art, Richard Branson.
In other words, the distinction between women succeeding as performers and men as bureaucrats only holds good in the middle ranks of the high earnings league.
The really high male earners in Britain today - people earning more than pounds 1m a year - are not principally captains of industry but are also in various ways performers, just like the top women.
This raises an intriguing possibility. It is widely appreciated that structural changes are taking place in the jobs market which have tilted the middle and bottom ends of the market towards women: the growth in service industry jobs, often part-time, which are taken largely by women, and the corresponding decline in full-time manufacturing industry jobs which used to provide employment for not- very-skilled men.
What has been less appreciated is the shift taking place towards the upper end of the job market: the squeeze on the general managerial jobs which have been the preserve of middle-aged, middle-class males, and the expansion of performance jobs in the new professions such as the media.
Even where the job has not changed, the way it is rewarded has. The development of performance-related pay has forced companies to measure management performance in quantifiable ways, rather than by making impressionistic assessments. Performance-related pay ought to help women break through the glass ceiling: the greater the extent to which their contribution has to be quantified, the greater the chance that real merit will show through.
If this shift of the job market towards performance is sustained, it will be good news for female job-seekers. But will it be sustained? I suspect the answer is yes, because it is part of the great global shift in comparative advantage which is now occurring at astonishing speed.
Put harshly, the comparative advantage of an advanced developed country such as the UK is no longer in mass-manufacturing, which can be done far more cheaply in East Asia, particularly mainland China. Such industries as remain will be under ever greater pressure to perform.
But our comparative advantage in new service industries will, if anything, increase. It is no disrespect to Jung Chang's wonderful Wild Swans to say that Western authors will continue to dominate world rankings, or to Chen Kaige's Farewell My Concubine to believe Hollywood will continue to dominate the world film market.
It is only a slight oversimplification, then, to say that the old male-dominated industries will move to East Asia, while the new service industries, in which men and women can compete on more or less equal terms, will remain here.
Of course not everyone can be performers: most jobs will remain routine. There is an inevitable rarity value associated with performance, even though the skills involved are sometimes hard for outsiders to see. (We all think we could write a better novel than Jeffrey Archer, but clearly we can't) So the shift of emphasis towards performance will not, of itself, revolutionise the position of women in the workforce.
But just as, on present trends, 10 years from now a majority of the jobs in the country will be done by women, so 10 years from now there will be a much higher proportion of them among Britain's top earners than there are today.
That is not just good news for women; it is, of course, also good news for the country as a whole. This is not just a British social issue. Making the most of the available skills in a country is the key to future prosperity. Glass ceilings waste talent. If structural change in the job market helps more women to break through them, then we will all be richer as a result.Reuse content